Stationary Aircraft Research Articles

Camp Century: The Untold Story of America's Secret Arctic Military Base under the Greenland Ice by Kristian H. Nielsen and Henry Nielsen (review).

Reviewed by: Camp Century: The Untold Story of America's Secret Arctic Military Base under the Greenland Ice by Kristian H. Nielsen and Henry Nielsen Antoine Bousquet (bio) Camp Century: The Untold Story of America's Secret Arctic Military Base under the Greenland Ice By Kristian H. Nielsen and Henry Nielsen. New York: Columbia University Press, 2021. Pp. 352. This recent translation of a 2017 research monograph by two Danish historians of science brings to the attention of English readers a well-publicized but now largely forgotten episode of the Cold War involving the construction of a U.S. Army base under the Greenland ice. Camp Century operated between 1959 and 1967 in the northwestern area of the Arctic territory, 150 miles (240 kilometers) from the still active U.S. Air Force base in Thule. Stretching across 6,000 feet (1,800 meters) of tunnels, Camp Century was home to up to 200 scientific and military personnel and powered by a portable nuclear reactor. Officially, the camp's purpose was to trial construction techniques in the Arctic environment and support scientific experiments. Its ulterior motive, concealed to its Danish hosts and only revealed in 1995, was in fact to prepare the ground for Project Iceworm, a planned network of 600 nuclear missiles hidden under the ice sheet. Camp Century delivers a fascinating and richly documented overview of the site's history and enduring influence. Across nine chapters, the book covers the sensitive political negotiations between the governments of the United States and Denmark, their careful management and vigilant oversight of any media coverage, the details of the camp's construction and everyday operations, the military R&D and scientific research conducted there, its eventual abandonment and more recent rediscovery. The text makes for a highly accessible and engaging read, a testament to the skills of both authors and translator. The writing is supplemented by abundant photographs and illustrations, bringing to life the history of the camp and helping to visualize the considerable accomplishments it entailed. Two dominant themes permeate the narrative. The first is the delicate political balance necessary to accommodate American military presence on Denmark's sovereign territory. For the Danish government, living up to its NATO commitments without arousing public disquiet at home was akin to walking a very narrow tightrope. Accordingly, media reporting on both sides of the Atlantic was closely monitored to prevent anything deemed too sensitive from slipping by. In all this, the cooperation between the two governments wholly bypassed the local Greenlandic authorities and population, [End Page 1234] whose views never entered into consideration. Only in the last few decades has their voice become more audible, notably regarding the clean-up cost of past American military activities, yet still only with limited purchase on the terms of the underlying Defense Agreement binding the United States and Denmark since 1951. The second theme concerns the battle pitting the American military's determination to impose itself on the Arctic geography against the environmental resistances encountered there. In the Pentagon's mind, Greenland was quite simply "the world's largest island and stationary aircraft carrier" (p. 176), its unforgiving climate an impediment to be overcome in the erection of a nuclear bulwark against the Soviet Union. The book certainly provides an engrossing account of the feats of ingenuity deployed to solve the engineering challenges met in durably installing human presence in one of the most hostile environments on the planet. The authors also underline the significance of the ice samples collected by the base's scientists in the development of contemporary climate science. The American decision to ultimately abandon Project Iceworm brings these two strands together, since it was primarily motivated by dual concerns over a refusal by the Danish government and the persistent challenges presented by the frozen environment. Indeed, the ice's ceaseless movement resulted in tunnel deformation and collapse over time, requiring continuous maintenance at great cost. The Arctic would thus have the last word, swallowing up the camp following its abandonment in 1967, its remnants progressively crushed by the shifting ice. As Nielsen and Nielsen narrate in the final chapter, concern has recently grown over the environmental hazard posed by the untreated sewage...

WITHDRAWN: Enhancement of texture analysis for stationary aircraft of satellite images using image capturing module

The present invention relates to a system for detecting stationary aircrafts, comprising an image capturing module for capturing image of stationary objects through satellite, a set of Gabor filters in association with the image capturing module for performing texture analysis of the captured images, a training module in connection to the system for providing an illustrative training procedure based on the captured images and further categorizing the captured images into aircrafts and non-aircrafts. Gabor filter, a linear texture detection filter, is used to essentially analyses whether there is particular frequency content in the image in specific directions in a placed area around the analysis point or region. The image capturing module is capable of testing the latest CMOS image sensor devices at a low cost with the embedded image capture capability that supports high-speed serial/parallel signals. Texture analysis refers to the texture quality characterization of the regions in an image. In the textural analysis, intuitive qualities, which are defined in terms like raw, smooth, silky or bumpy, are quantified as a spatial variance in pixel intensities.

Aircraft Detection System Based on Regions with Convolutional Neural Networks

Object detection in remote sensing imagery is an important topic of image processing researches. Detection of objects and regions from satellite imagery takes its place in various applications such as the detection of residential areas and agricultural lands, road lines, ships, as well as airport and hangar detections. As a more specific remote sensing imagery based object-detection process, a stationary aircraft detection system could serve as a model in some military applications. Such a model could serve the detection of stationary aircraft targets in airports. In the proposed study, a deep learning-based model detects the aircraft in the airports using the satellite images from Google Earth. The deep learning model uses the state of the art Regions with Convolutional Neural Network (RCNN). Firstly a built from scratch CNN design is used for the basic learning step of the system. Then, RCNN performs region detection, which anchors the stationary aircraft object bounding boxes. A large dataset containing aircraft images is preferred for the training of CNN. To validate the system, satellite images captured from airports in Turkey are used. The results of the study show that the proposed model successfully operates aircraft detection with high-performance rates. While the classifier network structure, which constitutes the first step of the study, produces 98.4% test accuracy, the proposed aircraft detection framework has successfully performed the aircraft identification process by producing matched bounding boxes in the test images.

Data-Driven Method to Study the Impact of Utilizing Electric Ground Power Systems on Airport Electricity Demand Profile

Gate electrification provides electricity and preconditioned air to stationary aircraft at airport gates as an alternative to the use of auxiliary power units. This includes a preconditioned air unit (PCA) and a ground power unit (GPU). This study aims to explore the impact of utilizing these units on the electricity demand of airports and analyzes the associated costs for both the cases of purchasing the electricity from a utility following a typical large commercial rate structure, and participating in the wholesale electricity market. The possibility of benefiting from solar energy to supply this electricity demand is also examined. The demand for gate electrification was measured at a gate at Des Moines International Airport in Iowa, U.S.A., and combined with other data including weather conditions and aircraft types to identify significant explanatory variables for electricity demand. This analysis revealed that ambient temperature is the main PCA demand predictor while aircraft type is the main factor driving the GPU demand. A linear regression model was developed to estimate the PCA electricity demand based on the ambient temperature. For the GPU, the typical demand was used based on aircraft type. This analysis shows that gate electrification used across all gates can contribute to up to 87% of the measured peak demand of the airport; the cost of participating in the wholesale market would be 57% less than following the current large commercial rate structure, and the airport can benefit from installing a photovoltaic system if the surplus electricity is utilized.

Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial

ObjectiveTo determine if using a parachute prevents death or major traumatic injury when jumping from an aircraft.DesignRandomized controlled trial.SettingPrivate or commercial aircraft between September 2017 and August 2018.Participants92 aircraft passengers...

Forced response analysis of a shaft-driven lift fan

The aim of this paper is to give an overview of the multi-bladerow forced response analyses carried out on a shaft-driven lift fan. The lift fan, used for vertical landing and take-off, is situated behind the cockpit and contains seven bladerows, of which two are counter-rotating rotors. The aim of the analysis is to determine the maximum vibration amplitudes of the two rotor bladerows for a range of configurations and speeds. Unlike typical axial-flow compressors, a significant part of the unsteady aerodynamic excitation is due to the distortion of the inlet flow over the cockpit and fuselage, a situation that creates several low engine-order harmonics. In addition, the main blade passing harmonics, arising from the bladerows immediately upstream, also need to be considered. Both the blading and the inlet geometry are difficult to discretize, the former due to overlapping bladerows and the latter due to complexity of the aircraft geometry including the louvred doors. The forced response analysis methodology is based on using an integrated aeroelasticity model which combines a non-linear, time-accurate, viscous unsteady flow representation with a modal model of the structure. The rotor vibration response was assessed at various shaft speeds for both stationary aircraft and at a number of flight speeds and yaw angles. Wherever possible, the findings were compared against measured experimental data and good agreement was obtained in most cases. The main conclusion is the feasibility of being able to use a numerical tool as an integral part of the design process, a route that allows a much more efficient coverage of the flight envelope compared to actual rig and engine tests.

The “Ground” Interference of a Carrier Deck

An estimate is made of the “ground” interference effect of the deck of an aircraft carrier. It is shown that in the extreme case of wing span equal to deck width the induced upwash is of the order of 20 per cent less than the usual ground interference value. Thus the landing characteristics of an aircraft should not be markedly affected.It seems that there should be a difference between landing an aircraft on a stationary aircraft carrier and on the ground, due to modification of the ground-interference effect by the finite width of the carrier deck, particularly if for some reason large aircraft are to be used. In this note an estimate is made of the magnitude of this effect.

Cellulose Lacquers - De-Icing Lacquer for Stationary Aircraft

Cellulose Lacquers - <i>De-Icing Lacquer for Stationary Aircraft</i>

On the Shielding of Noise Outdoors

Shielding of noise by buildings and walls can serve very usefully in the control of noise in communities. Fehr has reported a method, derived from diffraction theory, for computing the insertion loss of an impervious wall of infinite length and arbitrary height, placed between a point source and point receiver at arbitrary distances from the wall. Hayhurst has reported measurements on shielding by walls up to forty feet high, using stationary aircraft as noise sources. This paper presents further measurements on shielding by structures outdoors and attempts to correlate the available results with theory. In practice one must take into account, in addition to the idealized diffraction from an infinite shield, several factors including (a) finite size and detailed geometry of the shielding structure; (b) radiation from the ground image of the noise source; (c) attenuation contributed by the terrain, with and without the shield interposed; (d) refraction, scattering, and shadow effects caused by wind and temperature gradients and by turbulence. Studies of these effects have been made and procedures for estimating the amount of shielding obtainable in certain practical cases will be reported.

Disposal of the Carolines, Marshalls, and Marianas at the Paris Peace Conference

AT THE conclusion of the first World War the Carolines, Marshalls, and Marianas as possessions of Germany in the Pacific Ocean were subject to the disposition of the Principal Allied and Associated Powers. The islands, extending about 1,300 miles from north to south and 2,700 miles from east to wvest, do not have the total area of Luxembourg, the smallest of the United Nations. In 1920, the year of the first Japanese census, the population of the islands was about 52,000 of which over 48,ooo were natives. The economic significance of the islands was and is small, but the strategic value is very great. They have been compared to stationary aircraft carriers, cutting communications between Hawaii and the Philippines. In the last sixty years the flags of Spaini, Germany, Japan, and the United States, representing Europe, Asia, and North America, have flown either over all of the islands or important groups of them. With the outbreak of the Pacific war and the Japanese use of the Carolines, Marshalls, and Marianas, it could be presumed that the future political status of the islands would be discussed during the peace negotiations.' The Charter of the United Nations, which was written before the territorial settlements in the Pacific were made, provides for strategic areas in the trusteeship agreements over trust territories. American specialists at the Paris Peace Conference were aware of the strategic importance of the German islands in the Pacific Ocean. Dr. Stanley K. Hornbeck, specialist on the Far East and Pacific, believed that in an ideal solution all the islands would be placed under British or under American control. Realizing the impossibility of such a solution, he thought that the islands should be put at the disposal of the League of Nations, a solution which would place them either collectively or by groups under the administration of one or more powers as mandatories subject to certain limitations,